(a) A bus travels with a velocity of \(6 ms ^{-1}\). It then accelerates uniformly and travels a distance of 70 m. If the final velocity is \(20 ms ^{-1}\), find, correct to one decimal place, the:
acceleration;
(b) A bus travels with a velocity of \(6 ms ^{-1}\). It then accelerates uniformly and travels a distance of 70 m. If the final velocity is \(20 ms ^{-1}\), find, correct to one decimal place, the:
time to travel this distance.
Explanation
(a) \(u=6ms^{-1};s=70m;v=20ms^{-1}a=?\)
\(v^2=u^2+2as\)
â\(a=\frac{v^2 - u^2}{2s}=\frac{20^2 - 6^2}{2(70)}\)
\(a=\frac{400 - 36}{140}=\frac{364}{140}\)
\(âīa=2.6ms^{-2}\)(to 1 d.p)
(b) \(u=6ms^{-1};s=70m;v=20ms^{-1}t=?\)
v=u+at
â\(t=\frac{v - u}{a}=\frac{20 - 6}{2.6}\)
\(âīt=\frac{14}{2.6}=5.4s\)